What is a stowage factor?

A stowage factor is the volume that one unit of mass of a cargo occupies once stowed, including the void space between and within packages (broken stowage). It is quoted as m3/MT in metric or ft3/LT in imperial.

How do you convert m3/MT to ft3/LT?

Multiply m3/MT by 35.8814. That factor combines 35.3147 cubic feet per cubic metre with the 1.01605 metric tonnes per long ton. So 1.30 m3/MT is about 46.6 ft3/LT.

What does full and down mean?

A hold is full and down when it reaches both its volume capacity and its deadweight limit at the same time. If the cargo runs out of space first it is space-limited, and if it runs out of weight allowance first it is weight-limited.

Why are table values approximate?

Stowage factor varies with moisture, packing, compaction, and trimming. The table gives typical mid-range values for planning. For a fixture or load plan always use the figure from the cargo declaration or a recent draught survey.

Does a lower stowage factor mean more cargo?

A lower stowage factor means denser cargo, so more tonnes fit in the same volume. Iron ore at about 0.34 m3/MT is far denser than baled cotton at about 2.6 m3/MT, which means an ore parcel hits the deadweight limit long before it fills the space.

Cargo Stowage Factor Calculator

Stowage factor is the single most useful number in cargo planning: it tells you how much volume a tonne of cargo will occupy once it is loaded and trimmed. This tool gives you a searchable table of typical factors for common bulk, break-bulk, and bagged commodities, converts between metric and imperial units, and works out whether a given hold will be space-limited or weight-limited.

How it works

The stowage factor (SF) already includes broken stowage, so the volume a parcel occupies is simply mass multiplied by SF. Two limits decide how much you can load:

mass that fills the hold by volume = hold volume (m3) / SF (m3/MT)
loadable cargo = min(volume-limited mass, deadweight available)
volume utilisation = (loadable x SF) / hold volume

If the deadweight available is the smaller number, the parcel is weight-limited and space is left over. If the volume-limited mass is smaller, the hold fills up before you reach the deadweight. The imperial equivalent is found by multiplying the metric SF by 35.8814.

Example and notes

A 10,000 m³ hold loading wheat at 1.30 m³/MT can hold about 7,692 MT by volume. If only 8,000 MT of deadweight is available, the cargo is space-limited and the hold goes full before it is down. Switch to iron ore at 0.34 m³/MT and the same hold would take roughly 29,400 MT by volume — far more than any deadweight allowance, so ore is always weight-limited. Always trim and survey to confirm: table factors are planning figures, not a substitute for the cargo declaration.